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Researchers Examine Links Between Racism and Mental Illness

February 14, 2024

In the Columbia Mailman Psychiatric Epidemiology Training (PET) Program, fellows receive five years of funding and an invitation to think slowly and deeply about high-stakes issues in the field. During the program’s weekly seminar, faculty offer further food for thought. “For the first three, sometimes four years, we encourage fellows to make a presentation that doesn’t include data—focus on what interests you, what bugs you; tell us what you care about,” says Professor of Epidemiology Katherine Keyes, who codirects the program. “The scholars we produce know how to generate important questions with high-quality study designs underlying them.”

When it comes to asking important questions and identifying data sets robust enough to answer them, PET faculty members lead by example. Consider their inquiries into racial disparities in mental health diagnoses in the United States. “At the end of the day, we know that Black folks and people of color have very different lived experiences in this country and that has affected their health outcomes,” says former PET fellow John R. Pamplin II, MPH ’14, PhD ’20, now a Columbia Mailman assistant professor of epidemiology. (Read a Q&A with Professor Pamplin.) Racial differences have been well documented in asthma rates, cardiovascular disease, diabetes, maternal and infant health outcomes, even overall lifespan—and perhaps nowhere so starkly underlined as in COVID-19–related disability and death. Pamplin’s own doctoral research investigated differences in depression and suicidality, topics Keyes, MPH’06, PhD’10, herself a former PET fellow, has also investigated for more than a decade.

More recently, a contingent of PET faculty that includes both Pamplin and Keyes has turned their attention to the role of structural racism in the incidence of schizophrenia. “When it comes to schizophrenia and psychosis, there’s evidence that folks from marginalized racial groups—in particular, folks with Black, African, or Caribbean racial/ethnic identity in Denmark, the Netherlands, the United Kingdom, and the United States—have a higher prevalence of schizophrenia,” says Pamplin. “Those prevalences aren’t as elevated in places where those groups are dominant. It has to do with racial marginalization.”

Going back to the late ’80s and early ’90s, when he was a PET fellow, Ezra Susser, the Anna Cheskis Gelman and Murray Charles Gelman Professor of Epidemiology, investigated the role of maternal nutrition and famine in the etiology of schizophrenia. Over the last three decades, his work on schizophrenia has also delved into how paternal age and complications during pregnancy and birth affect adult-onset schizophrenia, as well as comparative analyses of international data. He sees structural racism in the U.S.—laws and systems of life that affect racial differences in such determinants of health as access to fresh vegetables and safe housing, even how healthcare is delivered and paid for—as a powerful theoretical framework for understanding disparities. “It’s not just for unpacking what’s going on,” he says. “It suggests that you also need changes to that system. Ideally, you would change the structures, and if you can’t change them, at least mitigate the effects.”

Prior work to untangle the causal components of disparities in psychiatric diagnoses—especially such multifactorial conditions as schizophrenia—has been suffused with bias and bad data. Consider the search for genetic explanations, says Pamplin. “The genetic variation among Black people is greater than that between Black and white folks,” he says. “That should give us pause as to whether genetic differences are the relevant factors to explain racial differences in health.” Susser—co-director of PET for 25 years, then director 2015–2020, and now again codirector with Keyes—urges humility in the quest for insights, particularly given the history of racism in psychiatry.  While diagnostic criteria—and treatment—for schizophrenia have come a long way in the last 50 years, race-based disparities persist in the rates at which people are diagnosed.

Susser and Pamplin began discussing the topic early in Pamplin’s doctoral studies—even after discounting for diagnostic bias, each had a hunch there was more to the story. At the time, however, solid epidemiological datasets weren’t available. In 2023, the American Journal of Psychiatry published Susser’s editorial with Els van der Ven, a clinical psychologist at the University of Amsterdam, on an analysis of ethnoracial differences in the incidence of treated psychotic disorders among nearly 6 million people insured by Kaiser Permanente Northern California.  “Despite the salience of Black-White disparities in schizophrenia,” they write, “the scarcity of high-quality population-based incidence data in the United States and the absence of measures of diagnostic bias (overdiagnosis of Black people) in incidence studies have limited our progress in understanding the underlying causes.”

PET scholars have a nearly 60-year legacy of responding to contemporary public health challenges, says Keyes, from HIV to young adult mental health and homelessness. “Structural racism is a huge determinant of population mental health, especially for racially minoritized populations,” she says. “We have a responsibility to develop measures, insights, into how these processes work.”